8.2—暴力枚举法—Subsets II

描述
Given a collection of integers that might contain duplicates, S, return all possible subsets.
Note:
Elements in a subset must be in non-descending order. e solution set must not contain duplicate
subsets. For example, If S = [1,2,2], a solution is:
[
[2],
[1],
[1,2,2],
[2,2],
[1,2],
[]
]

#include<iostream>#include<algorithm>#include<vector>using namespace std;bool comp(const vector<int> &a, const vector<int> &b){return a.size() < b.size();}vector<vector<int>> Subsets(vector<int> data){vector<vector<int>> result;if (data.size() <= 0)return result;int length = data.size();int num = pow(2, length);int num1 = pow(2, length - 1);sort(data.begin(), data.end());for (int i = 0; i < num; i++){vector<int> path;if (i == 0){result.push_back(path);continue;}for (int j = 0; j < length; j++){int temp = num1;temp = temp >>= j;if (i&temp){path.push_back(data[j]);}}result.push_back(path);}sort(result.begin(), result.end(), comp);auto it = unique(result.begin(), result.end());result.resize(distance(result.begin(), it));return result;}int main(){int a[3] = { 1, 2, 2 };vector<int> data(begin(a), end(a));vector<vector<int>> res = Subsets(data);for (int i = 0; i < res.size(); i++){if (res[i].size() == 0)cout << "[]";for (int j = 0; j < res[i].size(); j++)cout << res[i][j] << " ";cout << endl;}}